Interesting FTE (Also, 9mm AR = fun)

[Steelitall]

Turns out 9mm AR's dont much care for 85gr hollowpoints (or at least mine doesn't). PSA complete 9mm kit, anderson lower, DRT 85gr frangible HPs. Had a couple issues with the 40 of them I ran through the gun, most failures to feed (owing to the low weight i would imagine). This was the most interesting one though


No real complaint though, ran flawlessly with the other ~250 rounds i put through it (perfecta, wwb, winchester nato)



Notably, a 9mm AR is a very fun thing to have

 

[NickyBangBang]

Thanks for the info! Very helpful. Are you using a standard AR hammer?

 

[RDG]

http://www.northeastshooters.com/vb...k-headspace-KABOOM?highlight=9mm+AR+headspace

Not sure what's going on in that second picture with the round in the chamber but that's not a whole lot of case support. Check out this thread.

 

[warwickben]

That looks like a failure to eject more then Any thing else .

 

[bigblue]

Take some slow motion video.

Keep the chamber damn clean and make sure your rounds chamber properly. That chamber looks super shallow. Keep an eye on the spent casings and if you start to see bulges stop shooting.

I had three case ruptures with similarly unsupported cases.

 

[xtry51]

It's the weight. Stick with 115gr or 147gr.

 

[Steelitall]

Thanks for the info! Very helpful. Are you using a standard AR hammer?

I believe its a 9mm specific hammer, or at least PSA sells it as one. This was literally an everything but the lower kit (although I swapped the stock and muzzle break for legalities sake)

Take some slow motion video.

Keep the chamber damn clean and make sure your rounds chamber properly. That chamber looks super shallow. Keep an eye on the spent casings and if you start to see bulges stop shooting.

I had three case ruptures with similarly unsupported cases.

http://www.northeastshooters.com/vb...k-headspace-KABOOM?highlight=9mm+AR+headspace

Not sure what's going on in that second picture with the round in the chamber but that's not a whole lot of case support. Check out this thread.

It goes in farther normally, the shell got in the way of the bolt coming all the way forward, so that round basically slid to where you can see it. Or at least thats the assumption I've been working under; Next time I run it I'll check the depth again

It's the weight. Stick with 115gr or 147gr.

I didn't really figure it would cycle all that well, but the first mag I put them in turned out to be a bit of a problem child, so I ran the 8 of them left over split between the other two mags to double check. It was actually the very last one of them that did this XD. I got both 20rd boxes at dicks for <$10 each, so I was willing to "waste" them working through the rifle's break in. Everything else I shot was 115 or 124, no problems with either


I may now see the appeal of a slidefire stock....

 

[peterthefish]

I grabbed one of those a while back. I am a big fan of PSA.

 

[Steelitall]

Took it back out again yesterday, another ~220 rounds through. One magazine each of Remington UMC 115g JHP, Independence 115g HP, ZQI 123g Nato, WWB 115g FMJ, and Bite The Bullet 115g fmj (reloads). The rest was Perfecta. Only had one failure to feed, with a Remington UMC 115g JHP, about midway through the magazine. Possibly the magazine's fault, the mag catches are just dremeled out based on the measurements of a cheap caliper.

Biggest difference vs last time? Bought an Uzi LULA. Worlds of difference, especially as you get into the last 10 or so rounds. Of course, as soon as it arrived here, Midway puts the damn thing on sale :/

 

[Kisspik002]

I just picked up a stag 9mm AR...only had 1 FTF issue but wow 9mm ARs are a blast.
i assume it was an issue with the round not the rifle.